I was at a festival yesterday and bought my mom a jar of lilac jelly. I am not a fan of most sweet things, and had never thought about flower jellies before. So I looked it up, and found a site with links to a bunch of recipes for various flowers.
20 Delicious Flower Jelly Recipes You Should Try
And, incidentally, the lady who was selling these jellies said they were going fast, these might be a product worth selling! I bought one, and I don't think I have bought jelly or jam at a festival type thing for many years, if it appeals to me, and I'm not the target market for stuff like that, it might be worth your time to try selling some :D
I'm going to be eyeing my flowers now!